面向对象程序设计闯关题_2016(答案)

《面向对象程序设计》课程

闯关题

第一关

左门：编写一个Java Applet程序。要求程序运行后显示“How are you!”字样。

import java.applet.Applet;

import java.awt.Graphics;

public class test1 extends Applet{

public void paint(Graphics g) {

super.paint(g);

g.drawString("How are you!", 50, 50);

}

}

右门：编写一个可以计算矩形面积的Java Applet程序，要求矩形的参数通过网页传递给此程序。

第二关

左门：开发一个带图形用户界面（GUI）的程序，实现用户从键盘输入的字符串的复制功能。

右门：编写具有图形用户界面（GUI）的电话本管理程序，要求实现，当用户提交输入的姓名、工作单位、手机号码、住宅电话和办公室电话的信息后，弹出另一窗口，将输入的内容显示在其中。

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class Baymax_2 extends JFrame implements ActionListener{

JLabel [] lab=new JLabel[5];

JTextField [] txt=new JTextField[5];

String [] str={"姓名:","工作单位:","手机号码:","住宅电话:","办公室电话:"}; JButton button=new JButton("提交");

Baymax_2(){

setTitle("用户注册");

setSize(500,500);

setLayout(null);

JLabel biaoti=new JLabel("请用户注册信息");

biaoti.setFont(new Font("宋体",Font.BOLD,25));

biaoti.setBounds(140,20,300,30);

add(biaoti);

biaoqian(lab,str,this,0);

for(int i=0;i

txt[i]=new JTextField(200);

txt[i].setBounds(200, (130+i*40), 200, 20);

add(txt[i]);

}

button.setFont(new Font("宋体",Font.BOLD,20));

button.setBounds(200,380,80,30);

button.setFocusPainted(false);

add(button);

button.addActionListener(this);

setVisible(true);

}

void biaoqian(JLabel [] lab1,String [] str1,JFrame jf,int j){

for(int i=0 ;i

lab1[i]=new JLabel(str1[i]);

if(j==0){

lab1[i].setBounds(80, (130+i*40), 100, 20);

lab1[i].setHorizontalAlignment(SwingConstants.RIGHT);

}

if(j==1){

lab1[i].setBounds(200, (130+i*40), 100, 20);

lab1[i].setHorizontalAlignment(SwingConstants.LEFT);

}

lab1[i].setFont(new Font("宋体",Font.PLAIN,18));

jf.add(lab1[i]);

}

}

void jinggao(){

JFrame jg=new JFrame();

jg.setTitle("警告!!!");

jg.setSize(260, 120);

JLabel label=new JLabel("每个信息都必须填写哦！");

label.setFont(new Font("宋体",Font.BOLD,20));

label.setHorizontalAlignment(SwingConstants.CENTER);

jg.add(label);

jg.setVisible(true);

}

public void actionPerformed(ActionEvent e){

String [] str2=new String[5];

int a=1;

for(int i=0;i

str2[i]=txt[i].getText();

if(str2[i].equals("")||str2[i].equals(null)){

a++;

}

}

if(a!=1){

jinggao();

}

else{

JFrame user=new JFrame();

user.setSize(500, 500);

user.setTitle("会员信息");

user.setLayout(null);

JLabel [] lab2=new JLabel[5];

biaoqian(lab,str,user,0);

biaoqian(lab2,str2,user,1);

JLabel biaoti=new JLabel("会员信息");

biaoti.setFont(new Font("宋体",Font.BOLD,25));

biaoti.setBounds(160,20,300,30);

user.add(biaoti);

user.setVisible(true);

this.dispose();

}

}

public static void main (String arg[]){

new Baymax_2();

}

}

第三关

左门：编程实现下面计算器的图形界面。

右门：编程实现具有上面的图形用户界面的计算器，并实现其中简单的加、减、乘、除计算功能。

import javax.swing.*;

import java.awt.event.*;

import java.awt.*;

public class Baymax_Calculator extends JFrame implements ActionListener {

JPanel main=new JPanel(new BorderLayout());

JPanel head=new JPanel();

JPanel body=new JPanel(new BorderLayout());

JPanel body_north=new JPanel(new GridLayout(1,4,3,3));

JPanel body_west=new JPanel(new GridLayout(4,1,3,3));

JPanel body_center=new JPanel(new GridLayout(4,5,3,3));

JTextArea textShow=new JTextArea(1,35);

JButton [] button_north=new JButton[4];

JButton [] button_west=new JButton[4];

JButton [] button_center=new JButton[20];

//判断是否是第一次输入值

boolean whetherFirst=true;

//计算中间用于储存结果的值

double resultNumber;

//记录该计算是否有效

boolean whetherValid=true;

//用于储存当前运算符

String operator="=";

public Baymax_Calculator(){

super("Baymax-计算器");

setSize(600,450);

setVisible(true);

setmenu();

add(main);

main.add(head,BorderLayout.NORTH);

main.add(body, BorderLayout.CENTER);

setheader();

setbody();

pack();

}

//添加菜单

public void setmenu(){

JMenuBar menubar=new JMenuBar();

JMenu menu1=new JMenu("编辑(e)");

JMenu menu2=new JMenu("查看(V)");

JMenu menu3=new JMenu("帮助(H)");

setJMenuBar(menubar);

menubar.add(menu1);

menubar.add(menu2);

menubar.add(menu3);

}

public void setheader(){

head.add(textShow);

textShow.setEditable(false);

textShow.setFocusable(false);

textShow.setText("0");

}

public void setbody(){

JPanel kong=new JPanel();

body.add(body_north,BorderLayout.NORTH);

body_north.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

body.add(body_west, BorderLayout.WEST);

body_west.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

body.add(body_center, BorderLayout.CENTER);

body_center.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

String [] str_top={" ","Backspase","CE","C"};

body_north.add(kong);

for(int i=1;i

button_north[i]=new JButton();

button_north[i].setFont(new Font("宋体",Font.BOLD,15));

button_north[i].setText(str_top[i]);

button_north[i].setFocusPainted(false);

button_north[i].addActionListener(this);

body_north.add(button_north[i]);

}

String [] str_east={"MC","MR","MS","M+"};

for (int i=0;i

button_west[i]=new JButton();

button_west[i].setFont(new Font("宋体",Font.BOLD,15));

button_west[i].setText(str_east[i]);

button_west[i].setFocusPainted(false);

button_west[i].addActionListener(this);

body_west.add(button_west[i]);

}

String [] str_center={"7","8","9","/","sqrt","4","5","6","*","%","1","2","3","-","1/x","0","+/-",".","+","="};

for (int i=0;i

button_center[i]=new JButton();

button_center[i].setFont(new Font("宋体",Font.BOLD,18));

button_center[i].setText(str_center[i]);

button_center[i].setFocusPainted(false);

button_center[i].addActionListener(this);

body_center.add(button_center[i]);

}

}

public void actionPerformed(ActionEvent e){

String str=e.getActionCommand();//获取事件源的标签

if("0123456789.".indexOf(str)>=0){

handleNumber(str);

}

else if("+-*/=%".indexOf(str)>=0){

handleOperator(str);

}

else if(str.equals("1/x")){

handleOperator(str);

}

else if(str.equals("+/-")){

handleOperator(str);

}

else if(str.equals("CE")){

textShow.setText("0");

}

else if(str.equals("C")){

handleC();

}

else if(str.equals("Backspase")){

handleBackspase();

}

}

void handleBackspase(){

String str=textShow.getText();

int i=str.length();

if(i>0){

str=str.substring(0,i-1);

if(str.length()==0){

//如果去掉一个字符后文本没有内容了就初始化各种值

textShow.setText("0");

whetherFirst=true;

operator="=";

}

else{

textShow.setText(str);

}

}

}

void handleC(){

resultNumber=0;

operator="=";

whetherFirst=true;

whetherValid=true;

textShow.setText("0");

}

void handleOperator(String key){

if(operator.equals("+")){

resultNumber+=getNumberFromText();

}

else if(operator.equals("-")){

resultNumber-=getNumberFromText();

else if(operator.equals("*")){

resultNumber*=getNumberFromText();

}

else if(operator.equals("/")){

if(getNumberFromText()==0){

whetherValid=false;

textShow.setText("除数不能为0");

}

else {

resultNumber/=getNumberFromText();

}

}

else if(operator.equals("1/x")){

if(getNumberFromText()==0){

whetherValid=false;

textShow.setText("除数不能为0");

}

else {

resultNumber=1/getNumberFromText();

}

}

else if(operator.equals("=")){

resultNumber=getNumberFromText();

}

else if(operator.equals("+/-")){

resultNumber=resultNumber*(-1);

}

else if(operator.equals("%")){

resultNumber=resultNumber/100;

}

if(whetherValid){

long num1;

double num2;

num1=(long)resultNumber;

num2=resultNumber-num1;

if(num2==0){

textShow.setText(String.valueOf(num1));

}

else{

textShow.setText(String.valueOf(resultNumber));

}

}

operator=key;

whetherFirst=true;

whetherValid=true;

}

double getNumberFromText(){

double num=0;

num=Double.valueOf(textShow.getText()).doubleValue();

return num;

}

void handleNumber(String key){

if(whetherFirst){

textShow.setText(key);

}

else if(key.equals(".")&&textShow.getText().indexOf(".")<0){

//判断前面是否已经输入过小数点如果没有则在原文本后加上小数点

textShow.setText(textShow.getText()+key);

}

else if(!key.equals(".")){

//如果输入的不是小数点则直接在原文本后加上输入的文本

textShow.setText(textShow.getText()+key);

}

//再输入的值就不是第一次了

whetherFirst=false;

}

public static void main(String[] args) {

Baymax_Calculator f=new Baymax_Calculator();

}

}

第四关

左门：编程。要求实现一个具有图形用户界面的、窗口出现时可以播放音乐的贺卡程序。import javax.swing.*;

import java.applet.Applet;

import java.applet.AudioClip;

import java.awt.event.*;

import java.io.File;

import https://www.360docs.net/doc/ca14136935.html,.URI;

import https://www.360docs.net/doc/ca14136935.html,.URL;

public class Baymax_4 extends JFrame implements ActionListener{

AudioClip clip ,clip2;

JButton play = new JButton();

JButton stop = new JButton();

Icon icon=new ImageIcon("pikaqiu.jpg");

Baymax_4(){

setSize(500,500);

JLabel lab1 = new JLabel();

JLabel lab2 = new JLabel();

setLayout(null);

play.setBounds(30, 180, 180, 80);

add(play);

stop.setBounds(270,180, 180, 80);

add(stop);

lab1.setIcon(icon);

lab1.setText("播放");

play.add(lab1);

play.addActionListener(this);

lab2.setIcon(icon);

lab2.setText("停止");

stop.add(lab2);

stop.addActionListener(this);

try{

File file=new File("会呼吸的痛.wav");

clip=Applet.newAudioClip(file.toURI().toURL()) ;

}

catch(Exception e){}

setVisible(true);

}

public void actionPerformed(ActionEvent e){ if(e.getSource().equals(play)){

clip.play();

}

if(e.getSource().equals(stop)){

clip.stop();

}

}

public static void main(String [] arg){

new Baymax_4();

}

}

右门：编程实现图形用户界面如下图所示程序，要求当点击[播放音乐]按钮后开始播放音乐，点击[停止播放音乐]按钮后停止音乐播放。（注：按钮上的图片可以自选。）

第五关

左门：编程实现任意一个文本文件的复制功能。

右门：编程实现一个具有图形用户界面的电子书程序，要求程序能根据用户在图形用户界面上输入的文本文件名，在界面中显示文件的内容。

import javax.swing.*;

import java.io.*;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Font;

import java.awt.event.*;

public class Baymax_5 extends JFrame implements ActionListener{

JTextField txt=new JTextField(120);

JTextArea text;

Baymax_5(){

setTitle("图书查询");

setSize(500,500);

setLayout(null);

JLabel name = new JLabel("你想搜索的书籍：");

JButton select=new JButton("搜索");

name.setFont(new Font("宋体",Font.PLAIN,16));

name.setBounds(60, 20, 130, 30);

add(name);

txt.setBounds(190, 20, 130, 30);

add(txt);

select.setBounds(340, 20, 80, 30);

add(select);

select.addActionListener(this);

text = new JTextArea(20,30);

text.setLineWrap(true);

text.setFont(new Font("宋体",Font.PLAIN,16));

JPanel pan = new JPanel(new BorderLayout());

pan.setBounds(40, 80, 400, 400);

pan.setBackground(Color.red);

add(pan);

text.setEditable(false);

pan.add(new

JScrollPane(text),BorderLayout.CENTER);

setVisible(true);

}

void daochu(File file){

String str =" ";

try{

Reader in=new FileReader(file);

BufferedReader reader=new BufferedReader(in);

String s=null;

while((s=reader.readLine())!=null){

str=str+s;

}

text.setText(str);

in.close();

reader.close();

}catch(Exception e){

}

}

public void actionPerformed(ActionEvent e){ String str=txt.getText();

if(str.equals("JAVA")){

File file=new File("D:\\book1.txt");

daochu(file);

}

if(str.equals("JSP")){

File file=new File("D:\\book2.txt");

daochu(file);

}

}

public static void main(String [] args){ new Baymax_5();

}

}

第六关

编写一个包含2道单选题的考试程序，要求实现自动评分功能。（说明：所用数据库的类型和设计的程序类型可以自定。）